Understood. Thanks anyway for looking into it.
One additional oddity I noticed, in case it might trigger and idea as to why it's not working for me: I noticed last night that, when it keeps playing past the track I have selected to stop on, Now Playing stops scrolling the tracks. I have "Highlight Playing Tracks in the Playing Tracks panel: Select Track" selected.
In other words, my track list shows about 20 tracks. Normally, when 21 starts playing, #1 will go off the screen and #21 will show. But if I select the 19th track to stop on and it keeps playing past that track to 20 and 21, the tracks displayed do not change when I get past the 20th.
But like I said I understand that, unless the info above triggers some brainstorm, you've done what you can, and I appreciate you having taken the time.